package com.yixin.aps.common;

import javax.crypto.Cipher;
import java.security.Key;
import java.security.Security;

/**
 * DES加密解密
 * @author user
 *
 */
public class DesUtil {
	public DesUtil(){} 
	//使用默认的秘钥
    //private static String strDefaultKey = SdkConfig.getInstance().defaultkey;

	 private Cipher encryptCipher = null;
	 private Cipher decryptCipher = null;
	 
	 /**
	  * 指定密钥构造方法
	  * @param strKey  指定的密钥
	  * @throws Exception
	  */
	 @SuppressWarnings("restriction")
	public DesUtil(String strKey) throws Exception {
		 Security.addProvider(new com.sun.crypto.provider.SunJCE());
		 Key key = getKey(strKey.getBytes());

		 encryptCipher = Cipher.getInstance("DES");
		 encryptCipher.init(Cipher.ENCRYPT_MODE, key);

		 decryptCipher = Cipher.getInstance("DES");
		 decryptCipher.init(Cipher.DECRYPT_MODE, key);
	 } 

	 /**
	  * 将byte数组转换为表示16进制值的字符串， 如：byte[]{8,18}转换为：0813， 和public static byte[]
	  * hexStr2ByteArr(String strIn) 互为可逆的转换过程
	  * @param arrB 需要转换的byte数组
	  * @return 转换后的字符串
	  * @throws Exception  本方法不处理任何异常，所有异常全部抛出
	  */
	 public static String byteArr2HexStr(byte[] arrB) throws Exception {
		 int iLen = arrB.length;
		 //每个byte用两个字符才能表示，所以字符串的长度是数组长度的两倍
		 StringBuffer sb = new StringBuffer(iLen * 2);
		 for (int i = 0; i < iLen; i++) {
			 int intTmp = arrB[i];
			 // 把负数转换为正数
			 while (intTmp < 0) {
				 intTmp = intTmp + 256;
			 }
			 // 小于0F的数需要在前面补0
			 if (intTmp < 16) {
				 sb.append("0");
			 }
			 sb.append(Integer.toString(intTmp, 16));
		 }
		 return sb.toString();
	 }

	 /**
	  * 将表示16进制值的字符串转换为byte数组， 和public static String byteArr2HexStr(byte[] arrB)
	  * 互为可逆的转换过程
	  * @param strIn 需要转换的字符串
	  * @return 转换后的byte数组
	  * @throws Exception  本方法不处理任何异常，所有异常全部抛出
	  * @author 
	  */
	 public static byte[] hexStr2ByteArr(String strIn) throws Exception {
		 byte[] arrB = strIn.getBytes();
		 int iLen = arrB.length;

		 // 两个字符表示一个字节，所以字节数组长度是字符串长度除以2
		 byte[] arrOut = new byte[iLen / 2];
		 for (int i = 0; i < iLen; i = i + 2) {
			 String strTmp = new String(arrB, i, 2);
			 arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
		 }
		 return arrOut;
	 }
	 /**
	  * 加密字节数组
	  * @param arrB 需加密的字节数组
	  * @return 加密后的字节数组
	  * @throws Exception
	  */
	 public byte[] encrypt(byte[] arrB) throws Exception {
	  return encryptCipher.doFinal(arrB);
	 }

	 /**
	  * 加密字符串
	  * @param strIn 需加密的字符串
	  * @return 加密后的字符串
	  * @throws Exception
	  */
	 public String encrypt(String strIn,String encode) throws Exception {
		 return byteArr2HexStr(encrypt(strIn.getBytes(encode)));
	 }

	 /**
	  * 解密字节数组
	  * @param arrB 需解密的字节数组
	  * @return 解密后的字节数组
	  * @throws Exception
	  */
	 public byte[] decrypt(byte[] arrB) throws Exception {
		 return decryptCipher.doFinal(arrB);
	 }

	 /**
	  * 解密字符串
	  * @param strIn 需解密的字符串
	  * @return 解密后的字符串
	  * @throws Exception
	  */
	 public String decrypt(String strIn,String encode) throws Exception {
		 return new String(decrypt(hexStr2ByteArr(strIn)),encode);
	 }

	 /**
	  * 从指定字符串生成密钥，密钥所需的字节数组长度为8位 不足8位时后面补0，超出8位只取前8位
	  * 
	  * @param arrBTmp 构成该字符串的字节数组
	  * @return 生成的密钥
	  * @throws Exception
	  */
	 private Key getKey(byte[] arrBTmp) throws Exception {
		 // 创建一个空的8位字节数组（默认值为0）
		 byte[] arrB = new byte[8];

	  	// 将原始字节数组转换为8位
	  	for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) {
		  arrB[i] = arrBTmp[i];
	  	}

	  	// 生成密钥
	  	Key key = new javax.crypto.spec.SecretKeySpec(arrB, "DES");

	  	return key;
	 }

	 public static void main(String[] args){		 
		try {
			DesUtil de = new DesUtil("11QK7Tg4");
//			 String mobile = de.encrypt("13874880759", "utf-8");
//			 String token = de.encrypt("100007", "utf-8");
//			 String account = de.encrypt("1", "utf-8");
//			 String backUrl = de.encrypt("https://www.baidu.com", "utf-8");
//			 String notifyUrl = de.encrypt("https://www.baidu.com", "utf-8");
//			 String requestId = de.encrypt("1430107180642550531", "utf-8");
//			 String payMobile = de.encrypt("13874880759", "utf-8");
//			 String banks = de.encrypt("CMB", "utf-8");
//			 String type = de.encrypt("pc", "utf-8");
//			 String type1 = de.encrypt("mobile", "utf-8");
//			 String sign = de.encrypt("mobile="+mobile+"&token="+token+"&account="+account+"&banks="+banks+"&requestId="+requestId+"&backUrl="+backUrl+"&notifyUrl="+notifyUrl+"&payMobile="+payMobile+"&type="+type, "utf-8");
//			 System.out.println("mobile="+mobile+"&token="+token+"&account="+account+"&banks="+banks+"&requestId="+requestId+"&backUrl="+backUrl+"&notifyUrl="+notifyUrl+"&payMobile="+payMobile+"&sign="+sign+"&type="+type+"&type1="+type1);
			System.err.println(de.decrypt("3b512d289837a9ee", "utf-8")); 
			DesUtil des = new DesUtil("PkIP0Oz5");
			 System.err.println(des.decrypt(de.encrypt("aaaa", "utf-8"), "UTF-8"));
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		 
	 }

}
